Today, like many Saturdays, I’ll lace up my running shoes and hit the Centennial Trail for a long run. But unlike other Saturday runs, when I’m finished I’ll stack some stones by the river in remembrance and gratitude.

Last year, on Jan. 7, Sherry Arnold left her home in Sidney, Mont., for a morning run. She never returned, the only sign of her a single shoe beside the road.

As the news of her disappearance reverberated through the running community and made worldwide news, runners everywhere said prayers for Arnold.

Women runners in particular grapple with fears for our own safety. That could have been us. For weeks I thought about Arnold on every run.

To pay tribute to her and fight the fear that would steal my joy in running, I joined a virtual run for Arnold on Feb. 11, 2012, organized by her cousin Beth Risdon, who blogs at www.shutupandrun.net.

Thousands of runners around the world printed a bib and did the same. By that time two men had been arrested but Arnold’s body wasn’t found until March 21.

Before last year’s run, which I wrote about in this column, I invited other runners to join me and my family via a weekly email distributed by a local running club. It was last-minute notice, and a runner named Susan was the only other person who showed up.

As we ran together in Arnold’s honor we took the first steps of a friendship I’ve come to cherish.

While we immediately bonded because we were part of Arnold’s sisterhood as women, mothers and runners, Susan and I run the same pace and have a lot in common. So we made plans to run together again, with Arnold’s tragedy on our minds. There’s safety in numbers.

It didn’t take long before we were meeting twice a week to run five miles, forging a friendship through a mutual love of fitness. Since then we’ve run races together, encouraged each other in our goals and shared the daily details of our lives.

Earlier this week my husband Curtis commented that I’m always in a good mood when I come home from running with Susan. He’s right.

That’s the way friendship should be. It should support and strengthen our spirits the way exercise supports and strengthens our bodies. I’m lucky because I get to have both at the same time.

Still, I hate to think that it took a tragedy like Arnold’s senseless murder for me to meet Susan. I wish we’d met at a race or the grocery store. Though it feels like we were destined to become friends, our lives probably wouldn’t have intersected if we hadn’t run together in Arnold’s memory, which we will do again today.

I’ll admit, over the last year when Arnold has come to mind, I’ve usually pushed thoughts of her aside. It’s hard to think about how a vibrant, loving wife, mother, teacher and friend could have her life violently cut short while doing something she loved. While doing something I love.

Her cousin says Arnold was a woman who embraced life, running and people she loved. Her death left a hole. But her life left a legacy. I wonder how many other stories of friendship have sprung from the virtual run. I wonder how many more might sprout today.

Today, like many Saturdays, I’ll traverse the trail and feel gratitude for the beauty of the river, with Canada geese singing counterpoint to its boisterous descent. I’ll feel gratitude for a community that has such a wonderful place to run and where I feel safe most of the time. But more than anything I’ll feel gratitude that I can run with a friend and go home to my family.

Sherry Arnold deserved to do the same.